1. Field of the Invention
The present invention relates to display control systems. More specifically, the present invention relates to a technology useful for displaying appropriate images corresponding to the left and right sides on the screen of a display unit (e.g., a vehicle-mounted display apparatus) having a configuration in which a touch panel is provided on a liquid crystal display (hereinafter also referred to as a “dual-view LCD”), which can display different images when the same screen is viewed from the left side and the right side.
2. Description of the Related Art
Typically, LCDs (liquid crystal displays) are used as vehicle-mounted display apparatuses. Such a vehicle-mounted LCD is typically installed at the approximate center position of the center console in the vehicle cabin so that the screen can be viewed from both the driver seat and the front passenger seat. In known vehicle-mounted LCDs, a single LCD is used for displaying both a navigation screen and an audio/video (A/V) screen. Thus, when the navigation screen is viewed, the A/V screen cannot be viewed, and when the A/V screen is viewed, the navigation screen cannot be viewed. Further, when the vehicle is moving, a still-image screen such as a navigation screen or the like can be viewed, but a moving-image screen such as a TV screen or DVD screen cannot be viewed in order to ensure safety. With this configuration, since the TV screen or the like cannot be viewed when the vehicle is moving, it is inconvenient for a person in the passenger seat. In this case, dedicated LCDs may be installed for the driver seat and the passenger seat, respectively. However, except for some expensive large vehicles, the installation of two LCDs cannot be afforded since the space of typical vehicle cabins is limited.
Regardless of whether or not a navigation screen is displayed on the LCD, for the passenger in the passenger seat to view a TV screen or the like, he or she needs to perform required operations (such as selecting a source, performing setting, and switching the screen) using a touch panel disposed on the LCD screen or an operation panel disposed in the vicinity of the front seats (typically, on the center console). In this case, although there is no problem when he or she can continue to view the TV screen or the like that has been pre-set, it is practically unreasonable for the passenger in the passenger seat to occupy the LCD, since the driver also wants to see the navigation screen when the vehicle is moving. In such a case, since the passenger needs to perform the required operations again for viewing the TV screen or the like, it is very cumbersome for him or her to perform the operations.
Accordingly, as one variation of LCDs, the development of a “dual-view LCD” that can display different images when the same screen is viewed from the left side and the right side is in progress. When such a dual-view LCD is used as a vehicle-mounted LCD, the passenger in the passenger seat can freely view images (moving images on a TV screen or the like) that are different from images (on a navigation screen) the driver is viewing.
However, when a currently-available touch panel (i.e., an interface that allows input operation, upon the touch of an operation button, icon, or the like displayed on the screen) is provided on the dual-view LCD, an inconvenience occurs when in use. That is, the position of an image operation-button that can be viewed from the left side and an image operation-button that can be viewed from the right side may overlap each other. This is because, while the dual-view LCD displays images (e.g., information, such as operation instructions and various menus associated with operations) that are different from each other toward operators at the left and right sides, the touch panel is disposed on the LCD screen so as to be used by both the operators at the left and right sides. FIGS. 1A and 1B show one example of such a configuration.
In the example shown in FIG. 1A, a dual-view LCD 1 displays direction-indicating buttons (images) D1 to D8 for scrolling a map on a navigation operation screen 2R to an operator at the right side and displays various menu buttons (images) M1 to M3 on a DVD operation screen 2L to an operator at the left side. A touch panel 3 is disposed on the display screen of the LCD 1. As shown in FIG. 1B, on the touch panel 3, the position of the image direction-indicating button D7 viewed from the right side and the position of the image menu-button M2 viewed from the left side overlap each other.
When the position of the image operation-button D7 viewed from the right side and the position of the image operation-button M2 viewed from the left side overlap each other as described above, a determination cannot be precisely made via the touch panel 3 as to which button is operated, that is, as to whether the operator viewing from the right side (i.e., the driver in this case) performed the operation or the operator viewing from the left side (i.e., the passenger in this case) performed the operation. Due to the inability of identifying from which side the operation is performed, a microcomputer (not shown) connected to the touch panel 3 cannot cause the LCD 1 to display, on the display panel thereof, an appropriate image corresponding to an operation entered from the left or right direction (e.g., an image associated with map scrolling, when an operation is performed on the navigation operation screen 2R).
To overcome such inconvenience, there is a need to sort positions of operation buttons (for the navigation apparatus and the DVD player in the example of FIG. 1) for sources displayed on the display screen of the LCD. That is, there is a need to assign operable areas on the touch panel for respective sources. FIG. 2 shows one example of a layout when the positions of operation buttons (i.e., the operable areas on the touch panel) are assigned for respective sources. As shown, operable areas R1 to R4 are assigned, on the touch panel 3, for respective sources including a navigation apparatus, an audio apparatus (such as a radio receiver or a CD player), a DVD player, and a TV receiver. This arrangement can prevent the positions of the operation buttons for the different sources from overlapping each other.
As an example of technology related to the known art described above, Japanese Unexamined Patent Application Publication No. 6-186526 discloses a technology in which a single vehicle-mounted LCD can display two screens at the same time so that the two different screens can be viewed from the driver seat and the passenger seat. Further, for example, Japanese Unexamined Patent Application Publication No. 7-103778 discloses a vehicle-mounted navigation apparatus in which the range that can be operated by the driver is restricted while the vehicle is moving. In this technology, whether an operator is the driver or the passenger is identified, so that an operation area corresponding to the operator can be set.
In order to overcome the inconvenience (see FIG. 1B) that can occur with a dual-view LCD having a touch panel, the configurations in the known art requires such a layout that the positions of operation buttons for respective sources (i.e., the touch-panel operable areas R1 to R4 shown in FIG. 2) displayed on the display screen of the LCD do not overlap each other.
Such an arrangement (layout) does not cause a serious problem when the number of available sources (i.e., sources to be displayed on the LCD screen) is small, when the limited size of the touch panel is taken into account. However, when the number of sources increases, inconvenience arises. Specifically, the layout freedom is restricted, the screen design is restricted, and the external appearance is also impaired. That is, there is a problem in that the inconvenience illustrated in FIG. 1B arises, unless the operation buttons are laid out with care.